Influence of Passive Stiffness of Hamstrings on Postural Stability

Abstract The aim of the study was to explore whether passive stiffness of the hamstrings influences the strategy of maintaining postural stability. A sample of 50 subjects was selected; the final analyses were based on data of 41 individuals (33 men, 8 women) aged 21 to 29 (mean = 23.3, SD = 1.1) years. A quasi- experimental ex post facto design with repeated measures was used. Categories of independent variables were obtained directly prior to the measurement of the dependent variables. In stage one of the study, passive knee extension was measured in the supine position to assess hamstring stiffness. In stage two, the magnitude of postural sway in antero-posterior direction was measured, while varying the body position on a stabilometric platform, both with and without visual control. The margin of safety was used as a measure of postural control. The magnitude of the margin of safety increased significantly between the open-eye and closed-eye trials. However, although we registered a visible tendency for a larger increase of the margin of safety associated with lower levels of passive hamstrings stiffness, no significant differences were found. Therefore, this study demonstrated that hamstring stiffness did not influence the strategy used to maintain postural stability.

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Postural Stability in Athletes during Special Hurdle Tests without a Definite Dominant Leg

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18010172 ◽

2020 ◽

Vol 18 (1) ◽

pp. 172

Author(s):

Bożena Wojciechowska-Maszkowska ◽

Ryszard Marcinów ◽

Janusz Iskra ◽

Rafał Tataruch

Keyword(s):

Repeated Measures ◽

Postural Stability ◽

Center Of Pressure ◽

Balance Control ◽

Body Position ◽

Force Plate ◽

Lower Leg ◽

The Body ◽

Upper Limbs ◽

Body Balance

The purpose of this study was to analyze the body balance control of people walking and hurdling with or without a specific dominant leg in a monopodal position. This study involved 28 physical education students. The center of pressure (COP) was measured with a force plate under four conditions: single-leg standing (right and left) with eyes open and two upper limb positions (the arms were positioned in either a specific hurdle technique manner or alongside the body). A repeated measures analysis of variance (ANOVA) was conducted separately for five parameters of the COP in the medial-lateral (ML) and anterior-posterior (AP) directions under the four conditions. In the single-leg position, athletes without a dominant lower leg had better body balance than those with a dominant lower leg. The position of the upper limbs influenced the body position when hurdling. Accepting the correct position of the upper limbs helped to maintain balance (when overcoming hurdles). In hurdles, the position of the upper limbs should be improved to maintain postural stability and save this function for more demanding postural tasks.

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Can explicit visual feedback of postural sway efface the effects of sensory manipulations on mediolateral balance performance?

Journal of Neurophysiology ◽

10.1152/jn.00103.2014 ◽

2016 ◽

Vol 115 (2) ◽

pp. 907-914 ◽

Cited By ~ 13

Author(s):

L. Eduardo Cofré Lizama ◽

Mirjam Pijnappels ◽

N. Peter Reeves ◽

Sabine M. P. Verschueren ◽

Jaap H. van Dieën

Keyword(s):

Visual Feedback ◽

Repeated Measures ◽

Visual Information ◽

Postural Sway ◽

Center Of Mass ◽

The Body ◽

Body Center ◽

Explicit Feedback ◽

Dominant Frequencies ◽

Visual Conditions

Explicit visual feedback on postural sway is often used in balance assessment and training. However, up-weighting of visual information may mask impairments of other sensory systems. We therefore aimed to determine whether the effects of somatosensory, vestibular, and proprioceptive manipulations on mediolateral balance are reduced by explicit visual feedback on mediolateral sway of the body center of mass and by the presence of visual information. We manipulated sensory inputs of the somatosensory system by transcutaneous electric nerve stimulation on the feet soles (TENS) of the vestibular system by galvanic vestibular stimulation (GVS) and of the proprioceptive system by muscle-tendon vibration (VMS) of hip abductors. The effects of these manipulations on mediolateral sway were compared with a control condition without manipulation under three visual conditions: explicit feedback of sway of the body center of mass (FB), eyes open (EO), and eyes closed (EC). Mediolateral sway was quantified as the sum of energies in the power spectrum and as the energy at the dominant frequencies in each of the manipulation signals. Repeated-measures ANOVAs were used to test effects of each of the sensory manipulations, of visual conditions and their interaction. Overall, sensory manipulations increased body sway compared with the control conditions. Absence of normal visual information had no effect on sway, while explicit feedback reduced sway. Furthermore, interactions of visual information and sensory manipulation were found at specific dominant frequencies for GVS and VMS, with explicit feedback reducing the effects of the manipulations but not effacing these.

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Effect of Cardiovascular Fatigue on Postural Stability

International Journal of Athletic Therapy & Training ◽

10.1123/ijatt.18.5.38 ◽

2013 ◽

Vol 18 (5) ◽

pp. 38-40 ◽

Cited By ~ 1

Author(s):

Hamid Bateni ◽

Gina Leno ◽

Rebeca Manjarres ◽

Bailey Ouellette ◽

Mark Wolber

Keyword(s):

Outcome Measures ◽

Repeated Measures ◽

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Standing Position ◽

Treadmill Running ◽

Upper Body ◽

Mean Square Distance ◽

Squat Jumps

Context:Previous research has demonstrated that localized leg muscle fatigue induced by lower extremity exercises (e.g., squat jumps, sprints, and treadmill running) has an adverse effect on postural stability.Objective:To assess the effect of cardiovascular fatigue induced by upper extremity exercise on postural stability.Design:Repeated measures.Participants:Fourteen healthy young adults between the ages of 22 and 30 years (7 male and 7 female).Intervention:Participants performed an exercise protocol on an upper-body ergometer to induce cardiovascular fatigue.Main Outcome Measures:Postural sway, represented by center of pressure excursion, during bilateral standing in two different foot positions.Results:In a tandem standing position, mediolateral mean distance, root mean square distance, resultant power, and centroidal frequency increased signifcantly after inducement of cardiovascular fatigue.Conclusion:Cardiovascular fatigue adversely affects postural stability.

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The effect of support surface and footwear condition on postural sway and lower limb muscle action of the old people

10.21203/rs.2.10274/v1 ◽

2019 ◽

Author(s):

Meizhen Huang ◽

Kit-lun Yick ◽

Sun-pui Ng ◽

Joanne Yip ◽

Roy Cheung

Keyword(s):

Lower Limb ◽

Postural Stability ◽

Muscle Activation ◽

Postural Sway ◽

The Elderly ◽

The Body ◽

Support Surface ◽

Lower Limb Muscle ◽

Limb Muscle ◽

Age Related

Abstract Background: Diminished somatosensory function and lower plantar cutaneous sensitivity have been identified as a critical age-related change, which is related to postural instability in the older population. Footwear is suggested that can modulate the postural stability by altering the interface between the foot sole and the ground. However, it is unclear whether this footwear effect could also influence lower limb muscle activation for the elderly. This study aimed to investigate the footwear insole texture and supporting surface condition on static postural stability and lower limb muscle activation for healthy older people. Methods: This is a single-session study with repeated measurements. Twenty-three healthy older female stood on the firm (i.e., concrete floor) and foam surfaces with their eyes open in the three footwear conditions, namely barefoot, plain shoes and nodulous insole shoes, for 30 seconds. Static postural sway and muscle activation of biceps femoris (BF), vastus lateralis (VL), tibialis anterior (TA), and lateral gastrocnemius (LG) of the dominant leg were measured during each testing condition. Results: compared to firm surface, standing on the foam could significantly increase the body sway and lower limb muscle activation (p<0.05); compared to barefoot, when standing on the foam, wearing footwear significantly decreased the VL and TA muscle activation and minimize the postural sway in ML and AP direction, while the influence is larger for the nodulous shoes compared to the plain shoes. A positive correlation was observed between the lower limb muscle activation and AP (r=0.327-0.389, p<0.001) and total sway path length (r=0.317-0.427, p<0.001). Conclusions: footwear could improve the postural stability and decease the fall risk comparing to barefoot when the somatosensory input is in disturbance, while the improvement is larger when wearing nodulous insole footwear for the elderly.

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Virtual-Reality-Induced Visual Perturbations Impact Postural Control System Behavior

Behavioral Sciences ◽

10.3390/bs9110113 ◽

2019 ◽

Vol 9 (11) ◽

pp. 113 ◽

Cited By ~ 4

Author(s):

Harish Chander ◽

Sachini N. K. Kodithuwakku Arachchige ◽

Christopher M. Hill ◽

Alana J. Turner ◽

Shuchisnigdha Deb ◽

...

Keyword(s):

Virtual Reality ◽

Control System ◽

Postural Control ◽

Repeated Measures ◽

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Postural Control System ◽

Postural Responses ◽

The Impact

Background: Virtual reality (VR) is becoming a widespread tool in rehabilitation, especially for postural stability. However, the impact of using VR in a “moving wall paradigm” (visual perturbation), specifically without and with anticipation of the perturbation, is unknown. Methods: Nineteen healthy subjects performed three trials of static balance testing on a force plate under three different conditions: baseline (no perturbation), unexpected VR perturbation, and expected VR perturbation. The statistical analysis consisted of a 1 × 3 repeated-measures ANOVA to test for differences in the center of pressure (COP) displacement, 95% ellipsoid area, and COP sway velocity. Results: The expected perturbation rendered significantly lower (p < 0.05) COP displacements and 95% ellipsoid area compared to the unexpected condition. A significantly higher (p < 0.05) sway velocity was also observed in the expected condition compared to the unexpected condition. Conclusions: Postural stability was lowered during unexpected visual perturbations compared to both during baseline and during expected visual perturbations, suggesting that conflicting visual feedback induced postural instability due to compensatory postural responses. However, during expected visual perturbations, significantly lowered postural sway displacement and area were achieved by increasing the sway velocity, suggesting the occurrence of postural behavior due to anticipatory postural responses. Finally, the study also concluded that VR could be used to induce different postural responses by providing visual perturbations to the postural control system, which can subsequently be used as an effective and low-cost tool for postural stability training and rehabilitation.

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Impact of Virtual Reality–Generated Construction Environments at Different Heights on Postural Stability and Fall Risk

Workplace Health & Safety ◽

10.1177/2165079920934000 ◽

2020 ◽

Vol 69 (1) ◽

pp. 32-40 ◽

Cited By ~ 1

Author(s):

Harish Chander ◽

Alireza Shojaei ◽

Shuchisnigdha Deb ◽

Sachini N. K. Kodithuwakku Arachchige ◽

Christopher Hudson ◽

...

Keyword(s):

Virtual Reality ◽

Repeated Measures ◽

Postural Stability ◽

Postural Sway ◽

Center Of Pressure ◽

Postural Instability ◽

Postural Control System ◽

Environment Exposure ◽

Acute And Chronic Exposure ◽

The Impact

Background Falls due to postural instability are common in construction environments especially from a height. The purpose of the study was to investigate the impact of virtual reality (VR)-generated environments at different virtual heights on postural stability. Methods Nineteen adults were analyzed for postural stability, tested in real (No VR) environment and in three VR environments, randomly assigned, at virtual heights of 0 ft. (VR0), 40 ft. (VR40), and 120 ft. (VR120). Postural stability was quantified using center of pressure postural sway variables and analyzed using a repeated measures analysis of variance (ANOVA). Participants also completed a simulation sickness questionnaire (SSQ) before and after VR exposure and a presence questionnaire (PQ) after VR exposure. Findings Significant postural instability ( p < .05) was identified between VR and No VR, in which increased postural instability was evident in all VR conditions compared with No VR. Scores from SSQ were within a pre–post score difference of five and the PQ score was (104.21 ± 14.03). Conclusion/Application to Practice Findings suggest that VR environments, regardless of virtual height, induced increased postural instability, which can be attributed to visual sensory conflicts to the postural control system created by VR exposure. Participants’ subjective responses on SSQ and PQ confirmed the feasibility of using VR to represent realistic immersions in virtual heights. However, objectively, VR could potentially lead to postural instability, stressing caution. VR can be a potential tool for providing virtual high-altitude environment exposure for fall prevention training, however, more research is needed on postural adaptation with acute and chronic exposure to VR.

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Impact of Prolonged Exposure to a Slippery Surface on Postural Stability

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052214 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2214

Author(s):

Sachini N. K. Kodithuwakku Arachchige ◽

Harish Chander ◽

Alana J. Turner ◽

Adam C. Knight

Keyword(s):

Repeated Measures ◽

Postural Stability ◽

Prolonged Exposure ◽

Postural Sway ◽

Stable Condition ◽

Extrinsic Factors ◽

Intrinsic Factors ◽

Causative Factors ◽

Slippery Surface ◽

The Impact

Falls are extremely common in occupational settings. Intrinsic factors such as overexertion and extrinsic factors such as the supporting surface are causative factors of falls. The impact of prolonged exposure to a slippery surface on postural stability has not been previously studied. The purpose of the study was to analyze the effect of extended exposure to a dry and a slippery surface on postural stability. Eighteen males (age: 21.17 ± 3.38 years; height: 1.77 ± 0.08 m; mass: 89.81 ± 14.23 kg) were recruited and subjected to one-hour walking on a dry surface and a slippery surface on two different days. Participants’ balance was assessed using a force platform in stable and unstable conditions at 0, 30, and 60 min. Postural sway variables were analyzed using a 2 (surface) × 3 (time) repeated-measures ANOVA. Significant time main effects were observed in the stable condition with greater balance decrements at 30 and 60 min. Greater balance decrements were observed on the slippery surface compared to the dry surface in the unstable condition. The balance decrements can be attributed to overexertion due to the physiological workload of prolonged walking and to the potential gait modifications due to walking on the slippery surface.

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Postural sway during single-legged standing is dependent on the body position assumption strategy and supports the stability and mobility trade-off hypothesis

10.1101/215905 ◽

2017 ◽

Author(s):

Bogdan Bacik ◽

Grzegorz Sobota ◽

Artur Fredyk ◽

Kajetan J. Słomka ◽

Grzegorz Juras

Keyword(s):

Postural Sway ◽

Practical Implication ◽

Body Position ◽

Point Estimation ◽

The Body ◽

Quiet Standing ◽

School Grade ◽

Gait Termination ◽

Study Protocols ◽

Resultant Velocity

AbstractStudies that would address the problem of balance in the context of either the preceding or subsequent movement are scarce. We would like to propose the inverse relationship between stability and mobility as a general principle and that depending on the preceding action the postural sway characteristics in quiet standing would significantly differ. Thirteen female ballet school students were examined. Their mean age was: 15.1±0.95 years and the total of about 2500 (5th school grade) and 4200 (6th school grade) hours of dance training. The force plate was used to register ground reaction forces and moments. During the 30s trials subjects were to assume the Passé position in gait initiation (G-I) and gait termination (G-T) task condition. The following parameters were analyzed after restabilisation point estimation: the range of COP position, standard deviation of COP position, mean velocity in both planes and mean resultant velocity. The results showed significant differences between the G-I and G-T tasks in postural sway characteristics and confirmed our hypothesis. The practical implication of our study is the way of preparation to test position (PTTP) strategy might be as important as the measurement itself in the posture study protocols.

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Using visuo-kinetic virtual reality to induce illusory spinal movement: the MoOVi Illusion

PeerJ ◽

10.7717/peerj.3023 ◽

2017 ◽

Vol 5 ◽

pp. e3023 ◽

Cited By ~ 7

Author(s):

Daniel S. Harvie ◽

Ross T. Smith ◽

Estin V. Hunter ◽

Miles G. Davis ◽

Michele Sterling ◽

...

Keyword(s):

Virtual Reality ◽

Visual Feedback ◽

Repeated Measures ◽

Body Position ◽

Head Rotation ◽

The Body ◽

Spinal Movement ◽

Body Reference ◽

The Impact ◽

Virtual Body

BackgroundIllusions that alter perception of the body provide novel opportunities to target brain-based contributions to problems such as persistent pain. One example of this, mirror therapy, uses vision to augment perceived movement of a painful limb to treat pain. Since mirrors can’t be used to induce augmented neck or other spinal movement, we aimed to test whether such an illusion could be achieved using virtual reality, in advance of testing its potential therapeutic benefit. We hypothesised that perceived head rotation would depend on visually suggested movement.MethodIn a within-subjects repeated measures experiment, 24 healthy volunteers performed neck movements to 50oof rotation, while a virtual reality system delivered corresponding visual feedback that was offset by a factor of 50%–200%—the Motor Offset Visual Illusion (MoOVi)—thus simulating more or less movement than that actually occurring. At 50oof real-world head rotation, participants pointed in the direction that they perceived they were facing. The discrepancy between actual and perceived direction was measured and compared between conditions. The impact of including multisensory (auditory and visual) feedback, the presence of a virtual body reference, and the use of 360oimmersive virtual reality with and without three-dimensional properties, was also investigated.ResultsPerception of head movement was dependent on visual-kinaesthetic feedback (p = 0.001, partial eta squared = 0.17). That is, altered visual feedback caused a kinaesthetic drift in the direction of the visually suggested movement. The magnitude of the drift was not moderated by secondary variables such as the addition of illusory auditory feedback, the presence of a virtual body reference, or three-dimensionality of the scene.DiscussionVirtual reality can be used to augment perceived movement and body position, such that one can perform a small movement, yet perceive a large one. The MoOVi technique tested here has clear potential for assessment and therapy of people with spinal pain.

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Influence of the use of dental prostheses in balance and body posture.

Manual Therapy Posturology & Rehabilitation Journal ◽

10.17784/mtprehabjournal.2014.12.171 ◽

2014 ◽

Vol 12 ◽

pp. 171 ◽

Cited By ~ 1

Author(s):

Cristian Fernando Shiraishi ◽

Afonso Shiguemi Inoue Salgado ◽

Ivo Ilvan Kerppers ◽

Meiriélly Furmann ◽

Thais Barbosa De Oliveira ◽

...

Keyword(s):

Postural Balance ◽

Postural Sway ◽

Body Position ◽

Dental Prosthesis ◽

The Body ◽

Body Posture ◽

Dental Arch ◽

Body Balance ◽

Dental Prostheses ◽

Postural Responses

Introduction: The concept of body posture involves balance, neuromuscular coordination and adaptation. Automatic postural responses are adjusted to meet the needs of interaction between systems of postural organization and the environment. Postural control is to maintain body position seeking stability and orientation in space, and the maintenance of posture and balance is directly related to three main systems: visual, vestibular and proprioceptive, whose junction ensures body balance. Other factors may be related to this control, such as the use of prostheses, among them the dentures that provide the balance of the mouth and jaws, through neuromuscular balance, helping to balance the body as a whole. Stabilometry assesses postural balance through the quantification of postural sway in the orthostatic position on a force platform. Objective: To evaluate the influence of the use of dental prostheses in maintaining balance and posture through baropodometry. Method: The study included 10 women with an average age of 65 years old, all using dental prosthesis, which remained on the platform for 30 seconds, with the prosthesis, repeating the procedure without the use of the prosthesis. Results: As the postural balance is given by the sum of the balance of all body structures, where all must be wholesome, and may include dental arch, in this case replaced by dental prosthesis, there was a direct contribution of using it over body balance as a whole, since there was a decrease in the number of oscillations of the body centroid and radial displacement, among individuals who use dental prosthesis. Conclusion: The present study demonstrated that there is a direct influence of the use of dental prostheses on posture and body balance.

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